Process for the manufacture of salt.



0.1. WEIL. PROCESS FOR THE MANUFACTURE OF SALT imxlmglgsfirm Wham cHARLEs L. WEIL, or s r. CLAIR, memes-N, ASSIGNOB mo mnmoimcmzs'rsr. sum.

COMPANY, OEST. oLAm, MIGHIGAN, A eonrona'rrou or MICHIGAN.

manage.

The invent on relates to improvements in the manufacture of salt and consists in certain processes hereinafter fully explained by the employment of which two highly im: portant objects, among others, may be accomplished, to wit: (1 the control. of the proportions of the amounts of the various kinds of 'salt (that is kind with respect to fineness or coarseness of grain) made in a given time under practlca control of'the 'grainof the salt produced and the variation of such grain at will, and (2) the acceleration of that step of the process carried pnin the evaporating-pan by means other than but capable of cooperating with that employed toenable' the control of the character of' grain produced.

In the commercial production of salt, in addition to securing economy of operation and purity of product, it is desirable to control the size ofthe grains. Grains of difi'erent sizes are required for dlfferentuses and the demand varies accordingly. :It is accordingly of great importance to the manufacturerthat the process employed be c'apable of producing at the will of the op-. erator grains of such size as he may require at any particular time, and the invention herein described is designed, among other things, to meet that condition.

It may be premised that in tlie formati'on of salt by evaporating saturated brine, the size of the grains .of salt is acquired both at the surface of theliquor in the evaporating pans and beneath the surface; that is to say,

the particles tend to knit together on the surface and also to build themselves up beneath the surface, so that it is desirable to control both these operations. The size of the grains is accordingly aiiected by conditions at the surface and beneath the surface. This is particularly true -where evaporation is'notefiecte'd by direct application of heat to the brine in the evaporating pani but by heating the brine under pressure elsewhere, allowing'self evaporation and trans- Specification of Letters-Patent. Application filed May is, 1911. serial l fo. erases;

tion; of; the g'raining operation. .li'quid isu rectly heatedduring the formation ofgrain the phenomena are more comnormal conditions of operation or, in other words, the

.ditlon's as atpresent.

v rno cnss non ma mmnmc'rm or sum.

ferr in'gtheliquid, which graining has begun, to the evaporating pan forcomplepli'cate'd. Atthe surface. the principal condltlo'ns Meeting the size of the grains are theperiod duringiwhich they remain on the surface and the rateof evaporation. The princ pal condition beneath the surface affect ng' the size of the grain is the period during which the grain remains in the liqu'or before being'taken therefrom.

The process herein described deals with eachand all of these conditions and pro-- vides for the regulation of the size of the.

gains at the will of the operator to a nicety. ut 11} will be understood that some of the steps n the process herein described may be omitted without completely losing control of the size of the grains and without 'de-;

parting from the spirit of the invention or scope of the claims;

Many of the steps in the processimprove the manufacture of salt in other respects as Well as in that hereinbefore indicated. For

example, the period during which the grains remain at the surface is regulated preferably by air under pressure. This not only possesses many mechanical advantages but also eliminates the serious danger of producing impurity in the product, which would be incontrol of the size of the grains but also results in greater purity by the elimination of dust, cinders, etc, from over the pans "(which in actual practice often results in an inferior product) and also makes the rooms containing the evaporating pans comfortable (instead of almost unbearablev as at times at present) for those working therein I and secures a regular output regardless of weather conditions instead of making the output dependent upon the atmospheric con- In these and other ways the process" as a Whole produces salt of great purity and Patna-a June 8-, 1915..

Where the volved if be'aters or flippers were used, as

' gives the manufacturer greater control over 110,

its production, and several of the steps in the process in themselves represent important improvements in the .art.

In order that the process may be clearly understood, there is shown in the accompanying drawing an illustrative apparatus which may be conveniently used in practising the process. The drawing is illustrative only and admits of variation in nearly all its parts, and therein:

Figure 1 is a side elevation, mainly in diagram and partly broken" away and partly in section, of suitable apparatus for the practice of my invention, and Fig. 2 is a vertical section, on a larger scale, of a por tion of the evaporating or circulating-pan for the brine, with a portion of the air-pipes by means of which air is caused to effect a special and variable agitation of the surface mosphere, by reason whereo of the brine in said pan.

' In'the drawings I illustrate a system of apparatus for making salt from brine, whose parts, with the exception of certain features involving my invention, generally speaking, are of structures well-known in the art and do 'not require elaborate explanation.

Referring to the drawing, 10. designates a circulating and-pressure pump while 11 is a live-steam or pressure heater through which the brine passes, becoming heated to a comparatively high temperature; a temperature above its normal boiling point under atmospheric pressure. This is for the double purpose of causing gypsum to become insoluble and separate and of heating the brine to such a point. that upon subsequent release ofpressure and consequent self-evaporation it will become concentrated enough to deposit salt crystals. Element 12 is a filter through which the brine passes to remove the separated gy sum. Element 13 is a selfevaporator to w ich the brine passes from the filter12 and which is o en to the atthe pressure under, which the brine had been previously held or maintained through the resistance of the systemis released with evolution of vapor and the temperature ofthe brine is brought down to 226 Fahrenheit, which is the temperature of boiling brine at atm 0s pheric pressure." Element 14 is an evapo-- rator or circulatin'g-panwhich receives the concentrated brine from the .evaporater 13, and 15 a suction heater which receives the brine from the pan 14 and is in communication through a. pipe 16 with the pump 10. j The brine in proper quantities is ed to the heater 15 through a supply pipe '17, Evaporation ofthe brine takes place in the pan 14 with formation of salt grain andgrains already formed, a own,'fina.'lly reaching the temperature of about 200 Fahrenheit," and hence the salt is formed in the pan. Thepan is equipped with'a rotary rake com-,

building up of'those and the brine cools of brine, to the customary centrifugal machine 21 which is employed to partially dry the salt. The brine from the centrifugal machine 21 is saved and passed back to the,

system. The salt after treatment by the centrifugal machine is sent to salt-driers and then screened according to usual custom. The circulation of the brine through the system is continuous and, as hereinbefore explained, the increment of fresh brine necessary to maintain the volume is supplied through the pipe 17. The heaters 11-, 15 are of known character, and each comprises a cylindrical vessel containing small tubes 0 (not shown) through which the brinepasses and which -vessel exterior to the small tubes is kept filled with steam, live-steam being supplied to the heater 11. Usually the steam supplied to the heater 15 is the exhaust of auxiliaries. The filter 12 is also of-a known type and comprises a cylindrical vessel partly filled with small stones which present a large amount of surface for the deposit of gypsum or calcium sulfate carried by the brine.

The new features of the apparatus pertaining to a part of the present.inventionreside in the hood 22 covering the pan 14 arid having anoutlet 23. for vapor, and a main air pipe 24 supplied with air under pressure from a blower 25 -and having at suitable intervals branch pipes or nozzles 26 extending downwardly and inwardly nearthe outer edges of the pan 14 to near the normal level of the brine in the sameand constructed to cause a lateral passage of air over the hot brine.- The nozzles 26 are provided. with regulating valves 27 and the air leaving them will strike the surface of the brine obliquely and. create a marked agita-' tion on the surface of the brine, in the nature of a distinct ripple.

' A further feature of novelty connected with my invention and pertaining to the pan 14 resides in the delivery withinthe chamber formed by the hood 22 of a constant supply of heated air. This airmay be heated byany of the well-known means-for that purpose and will be delivered in large volume over the surface of th'e'briiie within 'the pan 14 for the purpose of accelerating evaporation from the brine and increasing the rapidity of the o eration taking place in the pan. The heate air may be supplied to the chamber below the hood 22 by means of .a ipe 28 and blower 29.

he essential features of novelty reside in the employment in "a system: such as demanta a j a,

scribed, of means, preferably air jetsjfor agitating the surface of the brine in the pair 14 for the purpose of securing a variation in grain and any special grain desired, and in the simultaneous introduction of heated air for evaporative purposes in. large volumev under the hood 22 and overthe surface of the brine during the agitation of the surface of the latter.

formed over the surface of the brine. The

agitation proposed b me is not the characterof agitation pro uced by the flippers.

of theprior art, but is special and ma be varied at will and is employed to contro the character of grain produced, that is with respectj to the fineness or coarseness of'the same, and to render it possible to op-- erate the system that any desired grain may I be secured. The pipe line 25 supplying the nozzles 26 with air will preferably have an air pressure of about pounds, gage. The

number of nozzles .26 emplo ed will vary with the size'of the pan 14 ut ordinarily there should be several of said nozzles employed, all operating at the same time. With the use of the air from the pipes or nozzles 26 or other means for variably agitating the surface of the brine, said surface is not only prevented-from scumming, but

the operator may, at will, by varying the degree ofagitation, secure such proportions of fine and coarse salt as maybe desired. It is of great importance that'a manufacturer may be enabled to secure variations in grain or kinds of salt produced since the requirements of the public demand the same. The systems heretofore employed for producing salt, and especially those analogous to the general system of heating brine under pressure and releasing the pressure, hereinbefore explained, were not controllable as regards the production of grained salt of uniform, adjusted finene to meet the various requirements of thee. and my invention has for one of its purposes to remedy the objection to these previous processes and to increase the utility of the same by'providing in the system suitable means for'seuring variations in the action taking place inthe evaporator pan so that salt of the particular kind or desired may be readily reduced.

inbeforeexplai'ned, so asto accelerate the evaporation by removing thb vapor and preventing condensation as the hot vapors" cool on leaving'the pan. The warm air will be driven into the chamber of the hood 24 by a fan or the like a, and this air being res ent with the surface of the brine in agitation, will rapidly take up moisture from the brine and carry the same through the outlet 23 ofthe hood, thereby hastening the opera tion of the general system and increasing the capacity thereof. The air used for agitating thesurface of the brine may also be warm air, if. preferred, so as to thereby faf cilitate evaporation.

By performing the graining evaporation in an atmosphere ofcontrolled composition, given by hood 22 in connection withsources of air 25 and \29, a control of the rate of evaporation and, thereby, of the size of salt granule, is given. I

I do not confine my invention to the de-' tails .of the apparatus hereinbefore' explained, nor in every instance tothe employmentof air under pressure. for creating the varied agitation or rippling of the surface of the brine, although the best results may be most conveniently andcertainly secured when air is used for this purpose. s

What I claim as my invention "and desire to secure by Letters-Patent is 1-.- The process of making salt from brine which comprises circulating brine through a suitable -heating system and delivering it in a hot saturated condition into a, main evaporating or circulating an maintained in an atmosphere of contro ed composition. and there allowing such brine to undergo self-evaporation, and controlling the kind of salt produced by a rippling agitation of the surface of the brine in said pan to an .extent governed by the size of grain desired.

2. The process of making salt from brine which comprises circulating brine through a suitable heating system and delivering it in a hot saturated condition into a main evaporating or circulating pan maintained in an atmosphere of controlled composition, there allowing such brine to undergo self-evaporation, and controlling the kind of salt PI'O'. duc'edby agitation of the surface of the brine in said pan to an extent governed by the size of grain desired, by fine jets of air underpnessure directed against such surface.

3. The process of making salt from brine which comprises circulating brine through a suitable heating system and delivering it in a hot saturated condition into a main'evaporatingor'circulatmg pan maintained in an atmosphere Of'COIltI'OllGd composition, there allowing such brine to undergo self-evaporation, and controlling the kind'of salt pro- In addition to the agitation o the surfac'e' J I of the brine I'preferably supply. warm airin large volume over such surface, as hereduced by agitation of the surface ofthe brine in 'said pan to an extent governed by the size ofgrain-desired, by fine jets of air under, pressure directed; obliquely. against such surface and'creatinga rip ling thereof. 7 4. The process of making sa tfrom brine which comprises circulating brine through a suitable heating system and delivering it in a hot saturated condition into a main evaporating or circulating pan maintained in'an .position of the atmosphere within the hood,

atmosphere of controlled composition there allowing such brine to undergo'self-evaporation, and controlling the kind of salt produced by a itation o the surface of the brine in sai pan to an extent governed 'by the size of grain desired, by a series of jets of air under pressure directed obliquely against such surface in an inward direction from the outer portions thereof. 5. The process of making salt which comprises circulating the through a hooded main'evaporating or circulatingpan in which the salt is formed, said pan being provided with a vapor discharge outlet and with means for controlling the comfrom brine brine and controlling thekind of salt produced by agitation of the surface of the brine in said pan to an extent governed by the size of grain. desired, by jets of air under pressure directed against such surface.

6; The process of making salt from brine comprising circulating the brine through a suitable superhe'ating system into a main evaporating or circulating-pan in which the of brine to an extent determined by the character of grain desired while constantly removing precipitated salt from the bottom of such body.

8. The process of making salt in varied grades from a body of bat self-evaporating brine which comprises inclosing a vapor 7 space abovethe surface. of such body in such manner as to permit a limited escape of vapors and agitating the surface of the body of brine to an extent determined by the character of grain desired by means pf air under .pressure directed against such surface while constantly removin precipitated salt from the bottom of such ody.

suitable superheating system into L n-pee 9. The process of making. salt in varied. grades from a body of hot self-evaporating brine which comprises, inclosing a vapor space abovethe surface of such body in such manner asto permit a' limited escape of vapors and agitating the surface of the body of brine to an extent determined b the character of grain desired by means 0 air under pressure directed obliquely against such surface in such manner as to create a rippling thereof while constantly removin precipi I tated salt from'the bottom of such ody.

10. The process of making saltin varied grades from hot self-evaporated saturated brine contained in a covered pan vented for the escapeof vapor, which comprises the agitation of the surface of the brine in said pan to an extent determined by the character of grain desired by means of air under pressure directed against such surface,-in the presence of a constant volume of heated air delivered over said surface, with constant removal of the salt so precipitated from the bottom of the pan.

' 11. The process of making salt from brine which comprises establishing. and maintaining a body of self-evaporating saturated brine underneath a vapor chamber while permitting a limited escape of vapor, transmittin hot self-evaporating brine into such body, delivering heated air to said body, controllably agitating the surface of said bodyand removing salt from the bottomof said body. V

12. The process of making salt from brine in a circulating system which comprises superheating brine under pressure, filtering the brine under pressure, releasing the pressure, delivering the released brine into an evaporating chamber .as a body of large surface, delivering heated air in large volume over said surface, rippling the sur face of the brine to precipitate salt crystals,

constantly removing such salt crystals and returning brine so treated for circulating through the system anew, fresh brine being added in the circulation prior to the superheating step.

'Signed at Clair and State of May, 1911. 7

Michigan, this 2nd day of CHAS. L. WEIL. Witnesses:

FRANK MOORE, J r., BENJ. R.-Wm1=r-Ln.

St. Clair, in the county of St. 

